U.S. Sen. Majority Leader Mitch McConnell says he felt he was on "pretty firm ground" when he delayed a vote to fill a Supreme Court vacancy in the final year of former President Barack Obama's time in office, and that he hoped to provide "an opportunity for the American people to speak up about who they wanted to make that decision."

So what would he do if a Supreme Court seat opened up in 2020, an election year for President Donald Trump?

The senator didn't give an explanation as to what was different in 2016, Obama's final year in office and the year he tried to appoint Merrick Garland to the seat that was vacated following the death of longtime Supreme Court Justice Antonin Scalia, and 2020. But he continued to say that appointing a new member to the Supreme Court, and lower courts around the country, is the best way to make a long-lasting impact on the nation.

When the U.S. tax reform plan was passed in late 2017, McConnell said, he remembered some people agonizing over particular details.

"I said, ‘Look, the only way the tax bill is permanent depends upon the next election, because people have different views about taxes in the two parties and approach it differently when they get in power. What can’t be undone is a lifetime appointment of a young man or woman who believes in the quaint notion that the job of the judge is to follow the law,'" McConnell said Tuesday. "That’s the most important thing we’ve done for the country, which cannot be undone."

Trump has appointed two Supreme Court justices since taking office — Neil Gorsuch, who took the seat Garland would have filled, and Brett Kavanaugh.

Filling those vacancies, McConnell said, was his first priority after Trump was elected.

"I remember election night being surprised like I’m sure all of you were that Donald Trump had won — I won’t ask for a show of hands for how many were predicting that, but I wasn’t," McConnell said. "Late that evening when we learned he was going to be president, the first thing that came into my mind is this opportunity doesn’t come along very often for my side."

On Wednesday, a spokesman for McConnell pointed to several statements the senator had made in the past about nominations, saying it's been more than 130 years since a Supreme Court nominee was confirmed by the Senate during a presidential election year while the Senate was controlled by the party opposite of the president.

“You would have to go back to the Grover Cleveland administration in 1888 to find the last time a Supreme Court vacancy in the middle of a presidential election year was confirmed by the Senate of an opposite party," McConnell told CNN in 2017.

As one might imagine, McConnell's remarks in Paducah following his actions in 2016 — a "decision of enormous consequences," he said Tuesday — drew some criticism.

Sen. Chuck Schumer said on Twitter that McConnell's focus on judges is telling.

Seriously it’s no surprise.@SenateMajLdr McConnell lives for GOP judges because he knows the GOP agenda is so radical & unpopular they can only achieve it in courts.